• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1349-1360
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• 2016

The purpose of this study was to identify the degree of quality of life (QoL) and its related factors in patients with Korean Chronic Obstructive Pulmonary Disease (COPD). With data collected by Korea National Health and Nutrition Survey in 2013, general and disease-related variables, pulmonary function test, and EuroQol-5Dimension (EQ-5D) were analyzed. The mean of EQ-5D index was 0.916 in patients with COPD and 0.941 in non-COPD. The EQ-5D index and its sub dimensions (mobility, self-care, usual activity, pain/discomfort, anxiety/depression) of COPD patients were significantly lower than that of non-COPD. However, difference in COPD patients' airway limitation was significant only for self-care of EQ-5D (${\chi}^2=9.50$, p=.013). The related factors of QoL in COPD patients were age, gender, level of education, quartile of household income, smoking status, and number of comorbid diseases. Based on the results, it is important to pay close attention to COPD patients' QoL as well as comprehensive interventions which possibly improve their QoL.

• Resources Recycling
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• v.26 no.6
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• pp.73-83
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• 2017

Used small household appliances have a wide variety of product types and component materials, and contain high percentage of black plastics. However, they are not being recycled efficiently as conventional sensors such as near-infrared ray (NIR), etc. are not able to detect black plastic by types. In the present study, an automatic sorting system was developed based on laser-induced breakdown spectroscopy (LIBS) to promote the recycling of waste plastics. The system we developed mainly consists of sample feeder, automatic position recognition system, LIBS device, separator and control unit. By applying laser pulse on the target sample, characteristic spectral data can be obtained and analyzed by using CCD detectors. The obtained data was then treated by using a classifier, which was developed based on artificial intelligent algorithm. The separation tests on waste plastics also were carried out by using a lab-scale automatic sorting system and the test results will be discussed. The classification rate of the radial basis neural network (RBFNNs) classifier developed in this study was about > 97%. The recognition rate of the black plastic by types with the automatic sorting system was more than 94.0% and the sorting efficiency was more than 80.0%. Automatic sorting system based on LIBS technology is in its infant stage and it has a high potential for utilization in and outside Korea due to its excellent economic efficiency.

• Resources Recycling
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• v.19 no.1
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• pp.33-39
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• 2010

The spheric sintered body with $6{\pm}2mm$ diameter was manufactured in a rotary kiln at $1125^{\circ}C$/15 min using green body formed by pelletizing the batch powder composing of coal bottom ash produced from power plant and dredged soil by 70:30, wt%. And the physical properties of sintered body (BD) were analyzed to confirm the possibility for applying to an absorbent to restore a contaminated soil. The sintered body had a giant pore above 100 ${\mu}m$ and a fine pore below 10 ${\mu}m$, and bulk density was 1.4. Also its specific surface area, porosity and void proportion were $12.0m^2/g$, 30.1% and 38.2% respectively. The crushed body (BD-C), produced by crushing a BD specimen into an irregular shape with a aspect ratio of about 2, was similar to BD specimen at bulk density and pore size distribution. But it had superior values of specific surface area, porosity and void proportion compared with BD specimen owing to a decreased apparent volume due to conversion of closed pore existed at interior of BD to open pore during a crushing process. The IEP of sintered body occurred at about pH=5, so the optimum pH condition of reacting aqueous solution could be known before bonding a microbe to the sintered body. Hence, the optimum void proportion and porosity of an absorbent can be obtained by appropriate mixing a BD with BD-C from the base data calculated in this study.

• Clean Technology
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• v.27 no.3
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• pp.247-254
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• 2021

In this study, an eco-friendly combustion process of waste 2,4,6-trinitrotoluene (TNT: 2,4,6-trinitrotoluene) was developed, and fundamental data for the quantity of the organic matter in the final combustion residues is presented. Because complete combustion of TNT is not possible theoretically, the combustion process was optimized to reduce organic matter content in the combustion residue by performing measures such as heating time changes, addition of propellant material, and after treatment using a high-temp electrical furnace. From the results, it was confirmed that the organic matter content in the residue could be decreased to 7 ~ 10% with each method. The quantity of the organic matter could be minimized by optimizing the combustion conditions of the process. With only a combustion time increase, the amount of organic matter in the combustion residues was measured at about 9 wt%. The environmental friendliness of the final exhaust gas was also confirmed by real time gas component analyses. In addition, the organic contents could be reduced by a further 2 wt% by applying an additional heat treatment using an external electric furnace after the first incineration treatment. In the combustion process of propellant added waste TNT, it was found that various TNT wastes could be treated using the same eco-friendly protocols because the organic content in the residue decreased in accordance with the amount of propellant. The amount of the organic matter content produced by all these methods fulfilled the requirements under the Waste Management Act.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.4 no.1 s.6
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• pp.15-29
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• 2005

Truck Shipment Safety Information, which is a part of the development of NERIS is divided into Optimal Route Guidance System and Emergency Response System. This research is for establishing an advance warning system, which aims for preventing damages(fire, explosion, gas-escape etc.) and detecting incidents that are able to happen during transporting hazardous materials in advance through monitoring the position of moving vehicles and the state of hazardous materials in real-time. This research is peformed to confirm the practical possibility of application of the advance warning system that monitors whether the hazardous materials transport vehicles move the allowed routes, finds the time and the location of incidents of the vehicles promptly and develops the emergency system that is able to respond to the incidents as well by using the technologies of CPS, CDMA and CIS with testing the ability of performance. As the results of the test, communication accuracies are 99$\%$ in freeway, 96$\%$ in arterial, 97$\%$ in hilly sections, 99$\%$ in normal sections, 96$\%$ in local sections, 99$\%$ in urban sections and 98$\%$ in tunnels. According to those results, the system has been recorded a high success rate of communication that enough to apply to the real site. However, the weak point appeared through the testing is that the system has a limitation of communication that is caused in the rural areas and certain areas where are fewer antennas that make communication possible between on-board unit and management server. Consequently, for the practical use of this system, it is essential to develop the exclusive en-board unit for the vehicles and find the method that supplements the receiving limitation of the GPS coordinates inside tunnels. Additionally, this system can be used to regulate illegal acts automatically such as illegal negligence of hazardous materials. And the system can be applied to the study about an application scheme as a guideline for transporting hazardous materials because there is no certain management system and act of toxic substances in Korea.

• Journal of Chest Surgery
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• v.43 no.3
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• pp.246-253
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• 2010

Background: Our objective was to review the long-term prognosis of patients with preoperative mild to moderate ischemic mitral regurgitation who underwent off-pump coronary artery bypass grafting. Material and Method: We prospectively followed 1,000 consecutive and systematic off-pump coronary artery bypass grafting patients who were operated on between September 1996 and March 2004; follow-up was achieved for 97%. Sixty-seven patients (6.7%) had mild to moderate ischemic mitral regurgitation at the time of surgery. Operative mortality, actuarial survival and major adverse cardiac event free survival were compared to assess the effect of ischemic mitral regurgitation. Result: Average follow-up was $66{\pm}22$ months. Patients with ischemic mitral regurgitation were older (p<0.001), had lower ejection fractions (p<0.001) and more comorbidities. Significantly more female patients presented with ischemic mitral regurgitation (p=0.002). There was no significant difference in operative mortality and perioperative myocardial infarction in ischemic mitral regurgitation patients (p=0.25). Eight-year survival was decreased in ischemic mitral regurgitation patients ($39.6{\pm}11.8%$ vs $76.7{\pm}2.2$, p<0.001). However, after correcting for risk factors, mild to moderate ischemic mitral regurgitation was not found to be a significant independent risk factor for long-term mortality (p=0.42). Major adverse cardiac event free survival at 8 years was significantly lower in ischemic mitral regurgitation patients ($53.12{\pm}12%$ vs $77{\pm}2%$, p<0.001). After correction for risk factors, ischemic mitral regurgitation remained a significant independent cause of major adverse cardiac events (HR: 2.31), especially congestive heart failure and recurrent myocardial infarction. Conclusion: In our series, patients with preoperative mild to moderate ischemic mitral regurgitation had a higher prevalence of preoperative risk factors than patients without ischemic mitral regurgitation. They had comparable perioperative mortality and morbidity, but, in the long term, were found to be at elevated risk for recurrent cardiac events.